1. Field of the Invention
The present invention relates to a vehicle driving posture (position) adjusting device adapted for adjusting a position of a driver who sits on a driver seat.
2. Description of the Related Art
As disclosed in Japanese Unexamined Patent Publication No. Sho 62-116324, there has been a conventionally known vehicle seat moving device provided with a pair of front and rear upstanding legs having different heights and borne on a floor panel in a vehicle interior, and slide rails (lower side sliders) adapted for supporting a seat cushion of a driver seat mounted on the upstanding legs slidably in forward and backward directions so that the slide rails are disposed in a front-raised sloping state. This seat moving device has a function of slidably moving the seat cushion of the driver seat in forward and backward directions of a vehicle body along the slide rails, a function of automatically adjusting a vertical position of the driver seat correspondingly to the sloping state of the slide rails, and a function of adjusting a tilting angle of the seat cushion in conjunction with the automatic adjustment of the vertical position of the driver seat.
More specifically, as shown in FIG. 17, the vehicle seat moving device disclosed in Japanese Unexamined Patent Publication No. Sho62-116324 is provided with lever arms 74 each disposed in a lower front portion of a seat cushion 71 and whose central portion is pivotally supported by a lag 73 borne at a front end portion of a slider 72. A front end portion of the lever arm 74 is pivotally supported by a lag 75 fixedly attached on a lower front end surface of the seat cushion 71. A rear end portion of the lever arm 74 is latched slidably along an arc-shaped window 78 formed on a vertical wing 77 of the lower side slider (slide rail) 76 i.e. a guiding groove whose central portion is curved concavely downward.
As the seat cushion 71 is moved forward from a rear position S3 shown with a virtual line to an intermediate position S2 shown with a solid line along the lower side slider 76 disposed in a vehicle body in a front-raised sloping state, the rear end portion of the lever arm 74 latched to the arc-shaped window 78 is guided to be lowered so that the lever arm 74 is shifted to a standing state. Accordingly, the front portion of the seat cushion 71 is pushed upward so that a seat surface is shifted to a front-raised sloping state. Further, as the seat cushion 71 is further moved forward from the intermediate position to the front position shown with a thin line S1, the lever arm 74 is shifted to a reclined state. Accordingly, the front portion of the seat cushion 71 is moved downward, and thereby a slope angle of the seat surface is reduced. Accordingly, the tilting angle of the seat surface becomes the same as that of the rear position S3.
As disclosed in the Japanese Unexamined Patent Publication No. Sho62-116324, the seat cushion 71 is disposed with a tilting means in its front portion. The tilting means includes the arc-shaped windows 78 formed respectively on the vertical wings 77 and the lever arms 74 whose respective rear end portions are slidably latched on the arc-shaped windows 78 The sloping angle of the seat surface is changed by making the seat cushion 71 move about a rear spindle 79 provided as a supporting point in a lower rear end portion of the seat cushion 71 in conjunction with forward and rearward movements of the seat cushion 71. Further, so-called hip points H1 to H3 which are sitting centers of a driver with respect to the seat surface can be vertically moved along an arc-shaped line Ma curved upward.
Thus, when a middle-height person J2 who is shorter than a tall-height person J3 moves forward the seat cushion 71 from the rear position S3 indicated by a virtual line to the intermediate position S2 shown with a solid line along the lower side sliders 76 disposed in the vehicle body in the front-raised sloping state, the middle-height person J2 can be move his hip point H2 upward correspondingly to his seated height by raising a setting height of the seat cushion 71. Accordingly, a view point I2 of the middle-height person J2 is matched with an appropriate line L so that a front vision can be properly secured.
However, when a short-height person J1 who is shorter than the middle-height person J2 moves the seat cushion 71 from the intermediate position S2 shown with a solid line to the front position S1 shown with a thin line along the lower side sliders 76, the sloping angle of the lever arm 74 becomes small so that a front end portion of the seat cushion 71 is lowered. Accordingly, the hip point H1 is moved downward, and a view point I1 of the short-height person J1 who has a short seated height is positioned lower than the appropriate line L. Consequently, it causes a problem that a front vision becomes worse.
On the other hand, when the tall-height person J3 who is taller than the middle-height person J2 retreats the seat cushion 71 from the intermediate position S2 shown with a solid line to the rear position S3 shown with a virtual line along the lower side sliders 76, the tall-height person J3 can move his hip point H3 to be lower than the hip point of the middle-height person J2. Accordingly, on this point, the view point I3 can be lowered to some extent as the seated height of the tall-height person J3 becomes higher. However, as the seat cushion 71 is retreated from the intermediate position B, the sloping angle of the seat cushion 71 in a rear-lowered sloping state becomes smaller. Accordingly, an upper body of the tall-height person J3 is shifted to a substantially upstanding state. Further, corresponding to this operation, a head portion of the tall-height person J3 is moved toward an upper front side so that a view point I3 of the tall-height person J3 is positioned in an upper front side from the appropriate line L. Accordingly, it causes a problem that a field of vision becomes worse. Furthermore, if the hip point H3 of the tall-height person J3 is moved to be lower than that of the middle-height person, and the sloping angle of the seat cushion 71 becomes small, the tall-height person J3 has to sit in a state of making his upper body substantially upstanding and stretching his lower knee toward a front side of the vehicle body in an unnatural angle. Accordingly, it causes a problem that operation of pedals becomes difficult, and driving operability becomes worse.